March 20Therewas a time where I had no memory; I thought this must be the GreatCompost.Since waking I heard Gardenertalking to me about what happened.Wewere transplanted once again into new plastic bags.Our stems and roots were trimmed.Our water diet was replaced with a new tea,one that is not salty.Our roots arehappy drinking this new concoction.Itis actually quite pleasant and is free from that sour taste.It makes me smile.I noticed that Sunflower and Broccoli arestill with us and we are all part of the crew.We may be leafless stalks but are sprouting new tiny leaf-buds.They are a vibrant green and brought a smileto Gardener’s face.Did I notice a smallbit of water in the corner of his eyes?Oh the magic in a topical meristem.Plants have an incredible capacity to regenerate, something thatGardener says he cannot do.I have ameristem on top that generates new leaves and a meristem below that generatesnew roots.As long as these meristemslive, we can regenerate ourselves.Thereare perils when you explore, when you venture off into the space frontier.You go into the unknown where the answers areno longer in the back of the book.Youobserve, thus gathering new knowledge to share with all those plants thatremain firmly root-bound on the Earth.And sometimes the price is paid with leaf and stem.

Gardener, Commander Burbank and the rest of the human crew closed all the hatches on the International Space Station before taking shelter in their Soyuz spacecraft. Broc, Sunflower and I stayed behind.

March 21We aregetting stronger every day.Both mymeristems are generating new leaves and roots.Sunflower and Broccoli are too.Soon, we will be ready to carry on our duties as active crew.This new tea is actually quite nice, my rootsare happy.I wonder what the new tea ismade from?

March 22Ioverheard my gardener talking to his crewmates about the new tea.He was reluctant to say how it was made.He said it was an ancient recipe, “Don’t ask,don’t tell”

March 23We arerecovering, growing greener every day.Istill only have only four tiny leaves but am able to return to my crewduties.Sunflower grows his leaves inpairs and now has two.Broccoli is inthe best shape with a bunch of new leaves coming out.For such a weak sproutling, he is one toughcrewmate.It is good to have him along.

March 24We got aradio call from my gardener’s gardener at 03:50, which woke everyone from adeep Saturday morning sleep.A piece ofspace junk, an old rocket body, was on a possible collision course with ourspaceship.All hands on alert!

We hadto prepare for an emergency evacuation.The chance of a collision was small but would be devastating so we hadto prepare.As aprecaution, we closed every hatch on our spaceship leading up to where ourescape capsule was docked.This tookabout half an hour.When closing thelast hatch leading from the Laboratory module, I volunteered to stay behindwith Sunflower and Broccoli.We may besporting small leaves but we are here standing tall, ready to do our job.Somebody had to stay behind to take care ofthe spaceship.With all the hatchesclosed and the ventilation turned off, it became real quiet, and stuffytoo.In weightlessness, there is nobuoyancy driven convection thus the cabin air remains stagnant.The droning of fans operating 24 hours a dayare required to keep the air stirred and of uniform composition.I have heard Gardener say that when workingbehind a rack or some confined place where there is no circulation, a pocket ofcarbon dioxide can build up and give him a headache.Sometimes he will set up a small portable fanwhen working in such a place.He shouldtake Sunflower, Broccoli, or me with him and perhaps he would not need thefan.Thus sealed in the Laboratorymodule for the collision safe haven, there was no air movement of any kind andwe felt the oxygen building up around our leaves.If this lasted too long we might suffocatefor lack of carbon dioxide.The spacejunk passed without hitting us.When mycrew opened the hatch and ventured back into the module, we were able to greetthem with a small breath of fresh air.

I am making a second set of flowers.They are all male flowers, full of fragrance for my crewmates to enjoy.I see Gardener smile.

March 8

Oh my aching roots!I am sick; my flower buds have wilted into little brown nubbins.My leaves have a fringe of brown that gets wider every day.The edges are curled and brittle almost like dried out leaves yet I have plenty of tea to drink.On Earth my leaves would be drooping but here in weightlessness they stay extended and from a distance they do not look sick.Perhaps my symptoms, thus masked, were not observed by Gardener as soon as they would have been if we were on Earth.Gardener is beside himself and is working hard to find a solution.This is not good; I feel in my roots that I may soon be going to the Great Compost in the ground.

March 10

Sunflower’s leaves are covered with brown spots.Both he and I are not feeling well.Broccoli seems to be doing OK.My gardener says it is something in the tea.The brown fringe on my leaves is growing.They do not sing anymore.

March 11

Broccoli is not doing well.His leaves are turning yellow.The brown spots on Sunflower are growing.We are dying from some space malady.Gardener is frantically working to save us.I have heard that there is nothing to fear about the Great Compost.My only regret is that I will not be here on the frontier to help in this mission.

March 13

My gardener figured out what was the matter and is working on a solution.It is the sour tea that we feed on.He told me it will take several days before the new tea is ready; these encouraging words are helping Broccoli, Sunflower and me to hold on.In the meantime, we have been repotted into new plastic bags and have a strict only-water diet.I understand when a gardener gets sick, sometimes they have to go on a diet.The compost tea is made mostly from vegetable scraps from their food pouches.He said their food has a lot of sodium in it, up to 1000 milligrams per serving and they eat 10 to 12 servings per day.This salt ends up in the compost tea and then goes on our roots.Sodium salts are very soluble in water and wash out from the soil thus ending up in the ocean.Potassium salts are less soluble and stay in the soil.Creatures that originated from the ocean live with sodium and use it for their essential membrane transport processes.Creatures that originated from the land use potassium and find high levels of sodium toxic.Ocean creatures, when they walk on the land, have to carry their sodium with them their bodies.Interesting how creatures adapt to what is found in their environment and what works well for one is toxic to the other.

March 15

I float on the edge of the brown abyss.My leaves have fallen off and I am merely a stalk.I am stripped of my call sign “Rose” let alone even being a zucchini.Sunflower has lost his leaves and now looks like a tangled piece of green yarn.Broccoli has only yellow leaves.I have one root in the Great Compost.I have heard that you should follow the dark.Call on me tomorrow and you shall find me compost!

In space I see things that are not there. Flashes in my eyes, likeluminous dancing fairies, give a subtle display of light that is easy tooverlook when I’m consumed by normal tasks. But in the dark confines ofmy sleep station, with the droopy eyelids of pending sleep, I see theflashing fairies. As I drift off, I wonder how many can dance on thehead of an orbital pin.

The retina is an amazing structure. It’s more impressive than film ora CCD camera chip, and it reacts to more than just light. It alsoreacts to cosmic rays, which are plentiful in space.

Cosmic rays are fragments of atoms—some the pieces of farawayexploded stars, some leftover debris from when the universe formed.These atomic fragments move at high speeds, and like X-rays, penetratedeep into material where they are eventually absorbed. Fortunately, ouratmosphere absorbs most of them, so they do not pose significantproblems for Earth dwellers (except for the many unfortunate effects toour bodies that we have collectively named “the aging process”).

Space is different. Free from the protection offered by theatmosphere, cosmic rays bombard us within Space Station, penetrating thehull almost as if it was not there. They zap everything inside, causingsuch mischief as locking up our laptop computers and knocking pixelsout of whack in our cameras. The computers recover with a reboot; thecameras suffer permanent damage. After about a year, the images theyproduce look like they are covered with electronic snow. Cosmic rayscontribute most of the radiation dose received by Space Station crews.We have defined lifetime limits, after which you fly a desk for the restof your career. No one has reached that dose level yet.

When a cosmic ray happens to pass through the retina it causes therods and cones to fire, and you perceive a flash of light that is reallynot there. The triggered cells are localized around the spot where thecosmic ray passes, so the flash has some structure. A perpendicular rayappears as a fuzzy dot. A ray at an angle appears as a segmented line.Sometimes the tracks have side branches, giving the impression of anelectric spark. The retina functions as a miniature Wilson cloud chamber where the recording of a cosmic ray is displayed by a trail left in its wake.

The rate or frequency at which these flashes are seen varies withorbital position. There is a radiation hot spot in orbit, a place wherethe flux of cosmic rays is 10 to 100 times greater than the rest of theorbital path. Situated southeast of Argentina, this region (called theSouth Atlantic Anomaly) extends about halfway across the Atlantic Ocean.As we pass through this region, eye flashes will increase from one ortwo every 10 minutes to several per minute.

Our brain interprets its sensory input and creates a map of reality.Philosophers have for centuries contemplated this question. As Platowrote, we see only the shadows of a larger and richer reality. On SpaceStation, I drift off to sleep, thinking of the nature of the “real”universe while observing my personal reality of dancing fairies.

Nature has a vivid imagination, more so than any human. By venturinginto unknown territory, discoveries will be made that tickle ourimagination and enrich our minds. On the frontier, you can once againsee the world through the eyes of a child.

I wonder why the sky is up, and why the stars abound?And why the Sun comes up each morn, and why the Earth goes ’round?I wonder what the Sun on Mars, would bring at dusk and dawn?I wonder what two moons would say, from Earth lit sky when Sun is goneI wonder if Mars mountain crags would be a sight to hold?I wonder if I’d dare to climb, how could I be so bold!I wonder when Man’s mind will grow, and cease to be so smallI wonder when we’ll venture forth, I hope before we fallI wonder if we’ll never dare, to reach up through the skyForever doomed to live on Earth, and this, I wonder why?

I often hear someone remark, “The chances of X happening are one in a million,” where X could be any number of rare events such as winning the lottery. When numbers become as large as a million, it is difficult for my mind to comprehend them-as compared to tangible objects that I can see, touch, and count. A thousand million makes a billion, making that number a thousand times more abstract.

I float in the space station cupola, looking out the seven windows of this faceted transparent jewel, observing the nighttime Earth. There are now seven billion people who call this planet home. It occurred to me that there are only six people who can say the same for space right now. What a privilege it is to be one of those six.

We have two new crewmates, Sunflower and Broccoli.Sunflower has a long stem for the size of his leaves.He is standing tall.Broccoli is small and weak.His sprout is so small that without the normal gravitational signals, surface tension forces keep his cotyledons from breaking free from the damp pigmat medium.Effectively, his first two leaves are glued down to a wet layer.Within a day or two mold takes over and the poor sprout dies.It grieves me to see them die.Life can be tough on the frontier.

February 21

Gardener picked one sprout out from the damp pigmat and stood him up with a piece of Kapton tape.An experiment he said it was.After a few days Broccoli was strong enough to stand on his own.He is still very weak and may not survive.

February 28

Sunflower is becoming a slackard.He is lazy.His stem is now about 40 centimeters long but is so thin and spindly that on Earth he would not be able to stand.A small breeze would cause his stem to buckle.But here in weightlessness, his stem does not need support so he is doing very little to strengthen it.The same thing happens to Gardener.He has two stems and they are getting spindly as well.But he is working hard to keep his strength.I know this because he takes me to the exercise machine when he works out and I get to drink real sunlight from the cupola windows while he pushes against heavy forces that simulate weightlifting on Earth.My gardener works out on this machine for two hours every day.Are we exploring the frontier or at health camp?Maybe a bit of both.Most of his effort is focused on his stems with exercises called squats and deadlifts.His stems may be thin but he is keeping them strong.

March 5

Broccoli survived the surface tension forces and the mold.He is now 10 centimeters tall and has deep rich green leaves.He must like drinking the compost tea.I still find it sour and not to my liking.My gardener also likes to put his nose close to Broccoli. I am not jealous, he has told me that I am still his favorite.

Lasers produce not only monochromatic light, but also a unique intensity profile. If you take a cross-section of the beam and plot the intensity, it is far from uniform. Mathematically, the profile takes the form of what’s known as a Gaussian distribution, or bell curve. This vastly simplifies calculations for the beam propagation. The divergence of a laser beam—how quickly it spreads—is much less than for an equivalent beam of broad-spectrum white light, such as the one produced by a spotlight.

If you project a typical two-millimeter-diameter laser beam 400 kilometers, or 240 miles (the altitude of Space Station), the resultant beam diameter is about 1 kilometer. This has two significant impacts. First, precise tracking is needed to keep this 1-kilometer spot on the 200- meter cross-section of Space Station from a distance of 400 kilometers. This is no small feat, as the Station is a moving target in the sky. Second, the intensity of the laser beam falls in proportion to its cross-sectional area. In this case, an initial beam of 2 millimeters expanded to 1 kilometer, reducing the intensity by a factor of about 250 billion. The rated output of the laser also will be reduced by this factor when viewed by the crew on Space Station, and so does not pose a threat to human eyesight. Please note the calculations are different when flashing an airplane, something that must be avoided. For the Space Station flash, the San Antonio astronomers used a one-watt laser and a gang of two 850-watt mercury-argon arc lamps. Both were clearly visible from my vantage point.

Space is my Mistress,and she beckons myreturn.Since our departure I think of youand yearn to fly across the heavens arm in arm.I marvel at your figure,defined by theedges of continents.You gaze at me with turquoise eyes,perhaps mistaken for ocean atolls.Youtease me to fall into your bosom,sculptured by tectonicrifts,only to move away as if playing some tantalizinggame.Time and time we turn together,through day, and night, and day,repeatingencounters every 90 minutes with a freshness,as if we havenever seen our faces before.We stroll outside together,enveloped by naked cosmos,filled withdesire to be one.So close,you sense myevery breath,which masks your stare through visor haze.We dance on the swirls of cloud tops,whileskirting the islands of blue.You know my heart beats fastfor you.Oh, Space is my mistress,andwhen our orbits coincide,we will once again make streaks ofaurora across the sky.